Hustad, P. D., Tian, J. and Coates, G. W., J. Am. Chem. Soc. 124, 3614–3621 (2002) discloses ethylene propylene copolymerization using a living catalyst system of bis(phenoxyimine)-based titanium catalyst activated by methylaluminoxane. The copolymer that was produced contained propylene present in syndiotactic sequences, but the article does not mention this and there was no recognition of this at the time of the synthesis set forth in the article or at the time of publication and there was no recognition or disclosure that the copolymer could accommodate more filler than if propylene were present in atactic or isotactic sequences.
Coates et al U.S. Pat. No. 6,562,930 discloses block copolymers containing syndiotactic block(s) and ethylene propylene blocks made using catalyst system of bis(salicylaldminato)titanium complex activated by methylaluminoxane. The ethylene propylene blocks contained propylene present in syndiotactic sequences, but the patent does not disclose this.